Pump and unloading means



March 16, 1937. I L; RAYHELD 2,073,710

PUMP AND UNLOADING MEANS Filed Jan. 2, 1935 .millllllllllllll lllll numg p linml" I MIN b;

Patented Mar; 16, 1937 UNITED. STATE-S PATENT OFFICE rum AND momma mainsCharles L. Rayfleld, Chicago, 11]., assignor, by

' mesne assignments, to Thermal Units Manufacturing Company, acorporation of Illinois Application January 2, 1935, Serial No. 2s

The present invention relates to an improved fluid pump and unloadingmeans for automatically equalizing the pump discharge and inletpressures as soon as the pump is stopped, where- 5 by starting of thepumpis greatly facilitated.

V In the Solomon E. Koplar Patent No. 1,986,584,

issued January 1, 1935, covering Refrigerant pumpingsystemsf, there isdescribed a refrigeeraht pumpingisystem utilizing a pump of thesamegeneral construction; and operation as the pump described herein, and towhich the present invention has been applied, although it will beapparentto one skilledin the art that the inven tion in its broadconcept may be utilized with other types of pumps:

In the above mentioned patent oil underpres sure is applied in thecommon chamber between the angularly disposed pumping sections forlubricating and sealing the pumpparts. m A feature of the presentinvention" resides in the provision of a thrust spring for each of therotative pump cylinders, these springs being so To this'end theref'ismounted at one end of one of, the pumping sections, a pair of discmembers which are arranged for separating move- 35 ment, one of thesemembers'being connected for rotation with the pump cylinder, andprovidedwith an annular .inclinedupper surface. A plu- 'rality of balls aredisposed between the aforementioned disc members, these ballsbeing-reaotained for rotationwith the discs, but free to move-outwardlyunder the influence of centrifugal'force over the inclined surface intoengagement withtheother of the discs; It will therefore be seen that as"these balls arethrown out- 45 wardly,-when the pump reaches apre-determined f speed, they act as wedges to force the discs apart.

i dvantage'is taken of this relative movement of the discsto operate avalve disposed in a by-pass onnection between the fluid inlet andoutletof ing detailed description taken in connection with theaccompanying drawing which mystrates a 55 single embodiment thereof, andin which:

, Other objects and ahvantages of the. present :j invention will morefully appear from the follow- Figure 1 is a view in=elevation of a pumpembodying the features of the present invention and having broken awayportions to show certain details of the pump parts in section;

Figure '2 is an enlarged transverse sectional 5 view taken through thecentrifugally actuated valve control means, taken substantially on lineII-II of Figure 1; and

. Figure 3 'is'a detailed plan view of one of the disc members of thecentrifugally operable valve 10 control means, showingthe annular groovedefining an inclined surface on its face.

As shown on the drawing:

As illustrative of my invention, I have chosen to show in Figure 1,pumping apparatus embodyi5 ing the features of the present invention,which, apparatus is adap d for usein a system re-.

. quiring' fluid to be c rculated therethrough under pressure, such asin arefrigerating system. Since my invention is primarily concerned withimprovements in the pumpand meansnor equalizing the pressure between theinlet and outlet connections for the fluid to be pumped, when the pumpis stopped, it is deemed unnecessary to x show the details of thepumping system, as these would be of conventional design. Consequently,the inlet and outlet connections with check valves therein, which wouldordinarily be connected into the'circulatory system, have been shown intheir relation to the pump proper. e

In general, the pump comprises a pair of anguiarly disposedpumpingsections A and B which are in end to end relationship and deflne -attheir juncture, a common chamber Ill.

. The pumping elements in each of thepumping sections are similarlyconstructed and operate in .the same manner. As aimatter'of fact, thesections A and .B operate in multiple and have their inlet andoutietconnections inter-connected. For

or each-set. being disposed in one of the bores in the p um'pin'gsection .B and the other piston of that particular setbeing disposed inone of the bores of the cylinder in section A. It will now I be evidentthat when the cylinder in the'pumping section is rotated by. a driveshaft M, which may be connected to a suitable source of power,

the sets of pistons will act as a coupling between -the cyllnderinsection B and the cylinder in section A, thereby causing the cylindersto. rotate -5 and the pistons to be reclprocated within their associatedbores.

Each of the rotatable cylinders is seated on a seating disc II and theseating surface of the cylinder is provided with port openings from eachof the bores Ii, these port openings being adapted to engage with asuitably disposed intake and discharge port which are connected to anintake line I! and discharge line connection IT.

The pump as thus described is well known in unnecessary In the presentconstruction, it is proposed to provide a thrust spring which willresiliently force the rotatably mounted cylinders against their seats.Referring to Figure 1, the cylinder II is provided with a central stemor shaft 11 at its seat end, this shaft being extended through asuitable opening l8 in the end of thehousing, and supported in ananti-friction bearing 19.

i is shown as comprising the usual type of ball bearings wherein theballs are contained between an innerand outer ball race.

The outer end of the shaft I1 is provided with a contracted threadedportion 20 which deflnes a shoulder Il-against which a disc or washer 22is held in abutting relationship by means of a nut 23.

surface of the shaft l1 and provides an abutment for one end of acompression spring 2 having its other end'abutting against the'innerball race of the anti-friction bearing Is. This spring, it isevidenisewill function to longitudinally force the shaft l'l towards theassociated end of the pumping section with the result that the cylinderII is forcibly. seated against the seat block or disc II.

The outer end of the, pumping section A is counter-bored as shown atIland has disposed therein the anti-friction means I! which wasmentioned above. There isalso mounted in the Icounterbore 28, a collaror sleeve 28 which terminates at its outer end in an annular ring shapfriction means 28. The anti-friction means 28 'rotatably, supports acontracted hub portion 2! of a disc 30 which is secured to the shaft I!for" rotation therewith.

Spaced above the disc II isa second disc 3| socket 33 of the disc 30. v

' The stem and socket connection between the discs I. and SI.enables'the discs to In the present instance, the anti-friction bearingThis disc projects outwardly'past the outer.

portion 21 which serves as a retainer'for anti-.

which is vprovided omits lower surface with a depending stem 32 which isin a central outwardly and upwardly, slanting surface 31, so that as theballs II are moved outwardly by centrifugal action, the balls will beraised slightly and contact the confronting surface a of the disc II toshift the disc 31 away from disc". 5-

For encasing the mechanism Just described.

there is provided a cap 38 which terminates at its base portion in anoutstanding flange 4. which is secured as by'bolts H to the end of thepump-/ ing section A.

This cap defines a chamber 42 which is in communication by means ofpassageways 43 and 44 with the inlet and outlet connections I and I1respectively.

In axial alignment with the center line of rctation of the disc 3],there is disposed a bushing 45 having a central bore which provides anextension for the passageway 44 and also serves as a valve seat for-acooperating valve pin ll. This bushing is provided with a diametral slota which serves as a guide for a pin "a supported in'the valve pin 46.

The valve pin 40 is slidably supported in a socket." which is disposedin the hub portion of the disc ll. this socket on the upper side of thedisc. At the inner end of the socket, the valve pin is supported on athrust ball member ll. Thev pin "a maintains the'pin 40 against movementrelative to its seat. v

The inlet and outlet connections I. and II are provided with'suitablecheck valves II and II respectively. a

' The operation of the valveand its control means will now beconsidered. when the pump is stopped and no fluid is being pumped intothe system, the balls It will be disposed at the inner portion of thegroove 31 and lie adjacent the axis of rotation of the' disc 30. In thisposition, the balls do not engage the disc SI, and the disc 3| will bein its lowermost position by yirtue ofv the action of gravity and thehigh pressure of the pumped fluid thereon. Since the valve pin 46 is atthis time out of engagement with the seat in the bushing 45,communication will be established from the inlet connection throughpassageway 43, the chamber 42. the passageway 44 and thence to theoutlet connection l1, whereby the pumping elements are lay-passed andany pressure which may be in the outlet connection dueito previouslyrunning the pump,,will be equalized with theinlet pressure. This willen'-' able the pump t'obe started under little or no "load.

When the pump is started, the disc II will be rotated-and the ballretainer disc 34 will also rotate and revolve the balls around the stemI2. As the pump continues to come .up to speed, a speed will be reachedwherein the balls 30 will move outwardly under the influence ofcentrifugal force and will besliglitly raised due to themclined surfaceor of the circumferentiaily extending oove, whereby the balls will bemus t into engagement with the confronting face of disc ll, to'raise-thedisc and bring the valvepin 46 against its seat. Seating of the valvepin will intercept communication through the chamber 42 between the ways48 and N, whereupon the pumping element will not be bypassed and fluidwill be pumped directly into the system. 1

From the foregoing, it will be apparent that the hereindescribed-invention describes novel means for seating of the rotativecylinders of the pump, and also provides a novel centrifugaldevice whichautomatically operates to control (I the by-passing o! the pump partsbetween the inlet and outlet connections or the p mp. wherev by when thepump is stopped, the outlet pressure,

is equalized with the inlet pressure so that the pump may be startedunder little or no load condition.- 1 a I am aware that many changes maybe made and numerous details of construction may be varied through awide range without departing from the principles of this invention andI. therefore, do not purpose limiting the patent granted hereonotherwise than necessitated by-the scope and spirit of the appendedclaims.

- I claim as my invention:

1. In a fluid pumping unit having a housing encasing pumping elements,and inlet and outlet connections for fluid to be pumped; a rotatablymounted member projecting to the exterior 'of the housing, said memberbeing rotatable in accordance with the pump speed, a cap disposed overthe projecting end of said member and cooperating with the housing todefine a chamber, a passageway from said outlet terminating centraily ofthe top of the cap 'and defining a valve seat, a valve element anotherpassageway associated with said seat,

connecting said chamber 3 and the inlet, and centrifugaliy operatedmeans responsive to the movement of said member for actuating the valveelement to control the fl'ow oi fiuid'through the passageways andchamber, said passageways and chamber cooperating to form a by-pass beween thepump inlet and outlet connections,

,2. A fluid pumping unit comprising an elongated housing, pumping meansin said housing including a rotatable member, inlet andoutletconnections for said means, a cap removably and abuttingly secured toone end of the housing and cooperating therewith to mm a chamber,passageways in the housing wall and cap wall connecting the inletandoutlet connections with said chamber to form a by-pass therethrough,a passageway in the cap wall being in end to end registration with-apassageway in the housing wall; the other end of the cap passagewayterminating in the cap wall to define a valve seat,

' and a centrifugally operated valve mechanism in said chamber connectedfor actuation from said rotatable member and cooperable with said seat vfor controlling the flow of fluid in said by-pass.

